1. Field of the Invention
The present invention relates to an electrolytic solution for an electrolytic capacitor, and an electrolytic capacitor using it.
2. Background Art
Electrolytic solution used for an electrolytic capacitor generally contains, as a main solvent, an organic compound such as γ-butyrolactone or ethylene glycol. As an electrolyte, ammonium salt or the like of carboxylic acid represented by maleic acid or citraconic acid is used. Alternatively, carboxylate of quaternized product of a compound containing alkyl-substituted amidine group is used as the electrolyte.
Recently, solder has been put into a lead-free state in order to reduce the amount of environmental burden material used. For responding to the lead-free solder, the temperature in a reflow process has to be increased to 260° C. In an electrolytic capacitor using the conventional electrolytic solution as discussed above, the heat in a solder reflow furnace whose temperature increases to 260° C., for example, vaporizes a small amount of moisture in the capacitor and increases the internal pressure in the capacitor. When the internal pressure is thus increased, a sealing material of the capacitor deforms and a mounting failure can occur.